The overall purpose of the Biostatistics Core is to provide support in the areas of research design, data entry and management, statistical analysis, and presentation of results for projects and researchers in the Midwest STDCRC. In addition, the Core will seek to develop new statistical methodology if the need arises. In addition to data managing data collected for specific projects the core will maintain the clinical database for the Bell Flower STD Clinic. Data required for the proposed projects will be abstracted from the BFC database and the Regenstrief Medical Records System. The existence of the Core also assures that any unforeseen statistical analyses or design problems will immediately be brought to the attention of professionals with expertise in these areas. Details on the specific methodologies and statistical analyses for each project appear in the individual proposals.